Textile mill spindles



Jam 1957 J. D. GLEITZ TEXTILE MILL SPINDLES 2 Sheets-Sheet 2 Filed Feb. 16, 1954 "infill/1dr! A IN VEN TOR Jseont D. 62 5/ rz 7a, a, /z ATTaRA/EV United States Patent 2,175,859 1 TEXTIEE'MILL SPINDLES.

Jerome lw Gleitz'; B'epper Pike: Village, Ohio," assignor, blterassignments, to Curtiss-Wright Corporation, MarquetteMetal Products Division, (Cleveland, Ohio, :1

The inventionrelates particularly to an improved composite metal blade. and whorl unit, inwhich a considerable portion is of'suitable light weight metal (strong aluminum allomgllereinafter aluminum), for; the purpose of enabling the-unit effectually tosupport and drive so called paper tube type?" (hereinafter tube type) bobbins while minimizingymass, hence handling cost and power requirement. Thetterm spindle, as hereinafter applied to the present -sub ject invention, means. the entire illustrated unit comprising a shaft, a whorl and a bobbin-supporting metal barrel.

Spindles of the type outlined, above, as compared to those which consist'of a relatively narrow steel shaft (called the bladelmou-nted tightly in a suitable whorl, are especially apt to be manufactured with built-in dynamic unbalance because of requiring at least three separately manufacturedparts tightly joined together into arigid unit. h

:wellknown to, theprior art the components can be effectually joined together 'by interference fitting (shrink and/or press fitting orcquivalent), and another serious problem is that of insuring the desired axi alrelative dimensions within. acceptably close tolerances in the spindle as a Whole while making certain that all exposed surfaces are smooth (no. open joints-which could, if present, entrainlintor dirt) and no rough or sharp edges which could snagorcut the yarn. The spindles are subject to rough. :usage, but are nevertheless expected to remain in service for years without developing any looseness between. the vinterfitted part-s, changein dimensions of the spindle or olf center rotation at. any exposed portion (frunout?-)... Thus. the composite spindles must strongly resi-stlateral. flexure' beyond the elastic limits of the component metals, particularly of the'alurninum, beingv frequently subjectedto. side strains as inthe dofling of heavy yarn packages andin having tosupport unbalanced loads rotating at high speed.

The principal. object of the present'invention is to provide a'greatly improved, superior quality, composite allmetal spindle ot .the .type discussed above, meeting: the various, requirements mentioned. Other objects, not already indicated, will be explainedor be made apparent later herein.

In the accompanying drawings, showing the preferred form of spindle and partially illustrating certain 'of the tools preferably used-to produce it:

Fig. is afragmentarycentral sectional View of the composite spindle hereof. V

Fig. 2 is a. similar view illustrating the various parts temporarily assembled into approximate alignment preparatory to being force-fitted together, the -view also showing more or less. disgrammatically (but incompletely) the assembling tools.

Fig. 3 is a reduced scale view showingthe'partly'finished spindle, resultingfrom the pressing operation by the tools ofFig. 2, asmounted for forming a center socket atthe topend of the composite bladeportion 1 Fig. 4 is an enlarged (double) scalefragmentary detail central sectional view (shading of central shaft purpose- 'ice , 2.- fully omitted) showingthe whorl associated parts of the finished spindle assembly somewhat more clearly than they can be shown in full-sealer Referring first to the finished spindle assembly or unit 1, as shown inFig. l, shaft 2, which corresponds to the blade in simpler forms of spindles, is of high quality, thoroughly heat treated, hard steel. As illustrated, the largest diameter port-ion. 3 of the'shaft is cylindrical and very smoothly finished (polished) for support by the upper bolster bearing (not shown). The shaft tapers downwardly to a footstep-bearing-engaging generally conical endportion 4 which is very accurately made and smoothly finishednas usual. The upper end portion 2a of the hard steelshaft 2, beyondthe bearingsurface 3, hastw-o-relatively different diameter cylindrical portions 5 and 6 which are in interference fitting relationship to respective p'ortions 7 and 8 of an axial bore 10ain the aluminum barrel 10,, between which portions 7 and 8; for a considerable distance along, the shaft; the shaft is free from contact with the. metal of the barrel as at clearance space The purposes of the clearance space 100 will be described later.

Thealuminum barrel 10 is preferably forging quality alloy for high strength and hardness; yet capable of being accurately-machined and finished: The barrel -10.is of slightly tapered form on its exposed surface. 10a, and has a reduced diameter cylindrical lower end portion 12 the principal, peripheral surface 1 2a of which is in interference fitting relation to a mating cylindrical bore 13. in the upper or :acornportion 14 of a steel whorl 1 5-.

The steel. whorl 15' has a driving-b'and-enga-ging or pul ley portion 16' defined: in -part by'lower and upper circular flanges-91.7 and 18. The upper flange portion 18 of the whorl is of relativelyheavy cross section, radially, and lies inv radial alignment with, the lower end of the reduced diameter portion 12 of the barrel 10, which associated regionsof the whorl and barrel must, so far as possible, be. effectually prevented from relative axial movement. The whorl. acorn 14 on its outer surface is gradually tapered upwardly as at 20'for loose centering engagement bythe' lower; end of the tube type bobbin (not shown) 'ancl'gradually tapered as. at 21 to form a bobbin-piloting smooth ran-1p. Above the ramp the top end surface or rim 22 of .the: whorl acorn very firmly abuts the shoulder surface: 23' of the aluminum barrel 10' all around the barrel to form a tight butt. joint 24, and the peripheral surfaces 'ofacorn. and barrel adjacent the joint 24 must be flush and smooth.

'At thetop of the spindle, for supporting and driving the bobbin, isa wear resisting tip 25-, preferably of steel or operatively equivalent material, shown in the form of a plughaving a smooth tapered peripheral surface 26 near its top 6116.. and a generally cylindrical reduced diameter shank portion 28 in interference fitted relationship to the wall surface of an axial cylindrical socket or bore 29 in: the barrel 10. The tight, flush butt joint 30 is very similar in. formation to. the .butt joint 24 at the top of the whorl acorn portion. 14, both jointsbeing prevented from coming into contact with the bobbin tube, as will be evident, when. the tube is mounted on the spindle.

All the above described parts must be made a nearly concentric as. possible on the rotational axis of the spindle. The spindle assembly as .a whole has a very important axial dimension, namely that indicated :at Q (lower conical shafttip to upper inner Wall or shoulder surface-32 of the whorl). That dimension must be held within a few one thousandths of an inch in order that the whorl portion '16 will be at proper height above the spindle rail for engagement with the driving hand and so that the same surface 32 canbeused as a base or reference point in locating 3.1125 the bobbin supporting portions of the spindle at proper height.

In the prior spindle constructions with which I am familiar and which are pertinent to the present subject, namely those having a hard steel center shaft; a barrel of light weight metal having a bore adapted for tight gripping interference fitting contact with the shaft, and a steel whorl, a sleeve or acorn portion of which has a bore adapted for tight gripping interference fitting contact with the barrel around its lower end portion opposite the barrel-embraced portion of the shaft, various weaknesses are present from the standpoint of required operational characteristics and/or in respect to practicability of high quantity production with the necessary precision in dimensions, surface finish, wear resistance, balance and the rest (already outlined).

If tapered surfaces in tight (e. g. force-fitted) contact are used to connect the components of the spindle, such surfaces are extremely difficult to manufacture with the required finish and taper and they exclude the possibility of variations in and maintenance of desired axial relationships of the interfitted parts. If, on the other hand, the mating parts are basically cylindrical, so as not to have the just mentioned disadvantages and others inherent in taper-fitting constructions generally, then another variety of difficulties is encountered, as will be discussed so far as pertinent to the present subject. Notably, when a suitable steel shaft (that is to say one with adequate strength and deflection resistance) extends for a sufficient distance into the receiving bore of an aluminum barrel adequately to reinforce the barrel and control its flexure at critical regions axially of the assembly (shaft should extend upwardly beyond joint 24 a distance at least as great as the average outside diameter of the whorl acorn), the shaft is apt to work loose and even move axially relative to the barrel without apparent looseness having developed. The problem is greatly complicated by unavoidable differences in the physical properties of the metals involved, elasticity perhaps being of greatest importance; and it is extremely diflicult to maintain proper dimensional allowance for interference fitting at certain critical regions. Furthermore techniques found acceptable and practicable for metal working generally have proven inadequate for composite metal spindles involving metals having a great difference in modulus of elasticity and in other respects.

If a uniform diameter portion of suitable length of a hardened steel shaft is adequately tight in a substantially uniform diameter axial bore in the bottom end portion of an aluminum barrel and the bored portion of the barrel is further reinforced exteriorly by the relatively stiff and rigid steel whorl acorn (e. g. force fitted around the barrel) the aluminum surfaces in contact with the steel shaft will probably not adequately resist axial movement and eventual loosening. If forced fitting is practiced, and the inserted shaft portion is long enough to accomplish its purpose, then the upper end of the shaft in passing into the bore will enlarge the bore diameter or at least adversely affect the shaft-gripping quality of its metal for a sufficient distance along the bore so that the shaft will not be gripped with adequate force to maintain a tight joint in the region of the lower end of the aluminum barrel (adjacent the bolster hearing), at which region the spindle as a whole is subjected to maximum concentrated stress when, for example, driving an unbalanced package at high speed or when otherwise (as during dofiing) being subjected to forces tending to deflect the spindle about its upper region of fixed support (bolster bearing) as a fulcrum. Additionally, assuming the same construction and that the inserted uniform diameter portion of the shaft is adequately gripped by the aluminum all along said portion of the shaft (which can be accomplished by relatively laborious shrink fitting of the parts as against forced fitting), axial movement of the shaft out of position nevertheless sometimes occurs. This is probably due to the fact that the stifli acorn portion 14 of the whorl-and particularly with the illustrated type of joint 24 etc. which, as required for external surface effects on the spindle, necessitates an abrupt reduction in diameter of the aluminum barrel material at the joint-introduces an abrupt change in the deflection resistance of the structure in the vicinity of the joint, above which, notwithstanding the reinforcing efiect of the hard steel core shaft portion 2a on the aluminum the deflection resistance is much less than in the region embraced by the whorl. In any event, if the shaft is tightly gripped by the aluminum barrel material in the region of joint 24, then when the spindle is mounted in a bolster-simulating fixture and given repeated deflection tests, the shaft frequently moves axially (said to creep) out of its original position in the barrel; and if the applied deflection force is suflicient slightly to separate the shoulders which form the joint 24 (applied force calculated to be insufficient to strain any part beyond the elastic limit of its metal) the shoulders will remain separated (cracked open) and the spindle will not then run true. The same applied forces do not open the joint 24 in the present construction, indicating that the steel shaft in the region of abrupt change in the deflection resistance of the spindle should be prevented from coming into contact with the aluminum. As illustrated, provision of clearance space around the shaft portion 2a below and above the plane of the joint 24 (e. g. a total of about three to four times the shaft diameter), leaves a considerable portion of the shaft free to flex independently of the barrel material. Thus the two metals, locally, can have no mutual restraining or other deleterious action on each other through friction.

Further, in the present construction, the shaft 2 and receiving bore surfaces of the aluminum barrel are so designed that the shaft is frictionally gripped by the barrel close to the bolster bearing engaging surface 3 of the shaft much tighter than at any other region along the shaft, so that, should any creeping action of the shaft in its receiving bore of the barrel occur, such will not disturb the desired axial relationship of the spindle components. The principles of construction described above can, if desired, be applied in connection with the mating surface portions of the barrel 10 and whorl 15 (not illustrated).

In Fig. 2, the steel shaft 2 is the only spindle component which is completely finished prior to the assembly operation depicted by that view. The barrel 10 of Fig. 1 (as described above) is represented in Fig. 2 by cylindrical barrel blank 10x, the whorl 15 by semi-finished whorl blank 15x and the tip or plug 25 is represented by semifinished plug blank 25x.

The barrel blank 10x of Fig. 2 is a cylindrical aluminum bar which has been fully end-finished and provided with substantially aligned fully finished bores at its two ends. Whorl blank 15x is fully formed as to its bandengaging lower end portions 17, 18 etc.; inner acorn bore surface 13, and bolster-collar-accommodating bore 32a, terminating in axial shoulder 32. Plug member or blank 25x is only roughly formed as to upper external diameter or head portion 26x, and the top end surface 26y of the blank is fiat. Ch'amfer 26z is provided on the head 26x as a pilot to facilitate entrance into socketed adapter or head A on the ram or plunger (not shown) of a suitable power press (e. g. hydraulic).

B, in Fig. 2, represents, diagrammatically, the platen of the press which carries above mentioned adapter A. C, partially shown in vertical central section, is a rigid tubular metal workholder or sleeve suitably fixed to the platen B of the press, substantially in axial alignment with the adapter A. Workholder sleeve C receives, as by fairly snug slip fitting relationship of its bore portion C to the bearing surface 3 of the shaft 2 of the spindle assembly, and, with adequate side clearance, the lower conically pointed end portion 4 of the shaft. Said portion 4 of the shaft enters a block D rigidly supported centrally by the workholder sleeve C. Thus the lower end portion of the hard steel shaft is strongly supported against axial and lateral movement, with the upper, unsupported,

end of the shaft accurately-held1 in alignment withthe adapter A of the ram. The top end portion' C" of sleeve C constitutes a support and lateral guide or positioning member on the platen for the whorl blank 15x. Whehlthe whorl blank 15x is placed, as by hand; into the illustrated positionin the press, said blank 15x is precisely centered with the shaft 2 (assumed already in inposition as shown) by slip-fittingsliding' engagement of the outer periphery of sleeve portion'C with the inside diameter surface 32a of the whorl blank 15x. Shoulder surface 32 rests upon the top end of workholder sleeve portion C, and provision for precisely locating that shoulder relative to theconically pointed, footstep-engaging lower end portion 4of the shaftZ comprises, as shown, a threaded connection D for lower shaft-centering and supporting block D. The shaft, as placed in the bore of sleeve C, is stoppedby a conicalsocket surface portion'D" of the block D, and the threaded connection D enables axial adjustment and precise retention of dimension Q (Figs. 1 and 2) as by tight sealing of locknut E against the lower end of rigidly mounted sleeve C. The inner and outer top edge margins of the upper end'of sleeve portion C", as shown in Fig. 2', are relieved by suitable chamfers. The bottom flange 17 of the whorl is maintained out of contact with the underlying adjacent top surface of sleeve C. The shaft-centering socket surface D in the adjustableblock Dis designed, as by having axslightly greater included angle than that of the footstep end 4 of the shaft, so as to engage the'lower endportio'n of the shaft at the outer limits of the rounded terminal portion of the shaft.

Referring now to the aluminum barrel blank 1'0x, which is next to be put into place (as by hand) for assembly by the press, the lower end of it's reducedldiameter portion 12 is preferably chamfered inside out for rough-piloting purposes, and further piloting relative to the whorl blank 15x is had by reason of an axially short cylindrical counterbore 34 in the upper end of the acorn-forming portion of the whorl blank. The counterbore 34, the bottom end of whichis' a gradually sloping bevel surface 34a, for guiding purposes relative to the barrel shank, is made slightly larger than the outside limit for the outer diameter of barrelshank cylindrical surface 12a. Mating surfaces 12a and 13 are so dimensioned as always to effect a tight press fit (in the magnitude of .00l.002" interference for example)", andj the mating surfaces are fairly smoothly finished, Suitably, the shank surface 12a of the barrel is gi ound cylindrically to the grinder relief undercut 35 adjacent shoulder: 23, and the bore surface 13' of theacorn ponion lft of the whorl is smooth reamed cylindrically, each to appropriate tolei ance dimensions for press fitting OfaIumi'num and steel. The, undercut35 and the pilot counterbbre S ice-operate to form a' more than adequate spaee for foreign material stripped orjwiped off the barrel shank surface 12a when the barrel blank is being pressed into final position in the whorl.

The lower bore (10d generally) in the aluminum barrel blank 10x has three diameters two of which form the finished surface (bore) portions 5 and 8 already identified andwhich} are connected by a smooth relativelyj long taper or bevel surfacefl3 7, These surfaces (7, Sand 37") can be made substantially concentric with each other by concurrent finish formation with a single stepped diameter reamer, guided by a carefully machined pilot hole the inner (upper) end portion of which extends, as at 36 c'onsidera bly beyond the position which the upper end of spindleshaft 2' will occupy in the finished spindle (see Fig. 1).

Cylindrically formed and relatively slightly stepped absolute concentrioity (and with asmoothconneeting circular rarnp or relatively long taper 38 to- 'a void cutting the" aluminumas the-'shaft'is pressed into final position). The grinding is effeeted simultaneously with that required to roughand finish form the various other peripheralsurfacesof' the shaft.- The bolster bearing contacting surface-Sisgivena special highfinishr The'pairs of mating surfaces-57'and'68have(with the preferred selection of materials, finishes and method of press fitting assembly, furthed discussed below) an interference or press fitting difference-in diameter on the order of .00 1, .002, thespeoified and maintained manfacturing tolerances preferably being such that the greater interference fitdifference will be between the lower surface pair 5-7'. Those lower mating surfaces extend downwardly to a region directly adjacent the upper rigid bearing support for the spindle in the bolster, henceare principally in the region of greatest strain when (e. g.) lateralforces are applied to any upper parts or portions of the spindle unit 1, as by unbalanced package loading or by the-attendants as already ment-ioned, or by other causes.-

One' important reason for employing a very small difference in diameter between the lower and upper bearing surface couples (5 7 and 6 8)- is so that while the barrel blank 10x is temporarily resting on the; whorl acorn (supported by counterbore -shoulder3'4'aas shown in Fig: 2*) the uppen'slightly' reduced diameter portion-(surface 6')-of the shaft, functions as avery effectual easy slipfit connectionbetweenthe shaft and barrel blank to holdYthela-t-terin alignment with the shaft axis, hence the plunger adapter'A of the press.

It might be noted, in view of thenext above paragraph that if the shaft receivingbore 10fy in the barrel blank 10x were to be made with a uniform diameter throughout? its effective length" (which might possibly save a little expense intooling" although rendering inspection more difficult) and a slightly greater diameter were provided at shaft surface 5 than at surface 6, (with the view to using 6; as pilot bearing and 5 for, the necessary very tight force fitting in the barrel shank near the bolster bearing'flthen the-upper bearing couple (6"8") could not possibly be manufactured t-o serve as anjeasy slip fit in the upper end of such above-assumed uniform diameter receivingbore (so as to enable hand placement of the barrel; blank; cf. Fig; 2)" and to serve additionally as an adequately snug pilot, or shaft-and barrel-aligning means, as above the whorl acorn, which, in order to prevent the possibility of run-out at (e. g.) the tip, or upper end portion of the spindle, necessarily requires at least a light interference fitting relationship between the parts at or near the upper'end' of shaft 2.

Additionally; if onewere to depend solely upon a difference in diameter between portions.5 and 6 of the shaft (againassuming a cylindrical unstepped receiving bore in the barrel blank 10x for such shaft portions 5 and 6 which would be ditficult to manufacture and inspect), then in order to assure that both portions 5 "and 6.wo'uld be adequately tight in such single diameter bore, the difference in shaft diameters would either be too small to admit of speoifying practical manufacturing tolerances or the lower portion 5'W0llld have to be so large relative to the receiving bore in the barrel that said lower portion 5"would have to cut or scuff its way through the aluminum rather than forcing its way through by slightly com'pressingor locally expanding the aluminum (as done in the practice of the present invention), assuming that the pressing operation could actually be performed without damaging the assembly beyond repair.

Referring further to the tip blank 25x as positioned in and on the top end of the barrel blank 10x, Fig. 2, the shank portion 23 of the plug is enabled to easily enter the smooth bore or socket 29 of the barrel blank a short distance by reason of a reduced diameter pilot end portion 40 on the shank, which is made (e. g.) between one half and two one thousandths of an inch smaller than the minimum specified limit of the socket diameter (at 29) and of sufiicient length to hold the blank 25x stably in upright position prior to press fitting. Shoulder 41 is a. smooth taper similar to 38 on spindle shaft 2, to avoid cutting or scufi'ing of the aluminum in bore 28. The interference between tip shank 28 and its receiving bore 29 in the barrel blank is preferably slightly greater than any of the other force fitting relationships earlier described, since the barrel metal around the shank 28 is not confined as it is at the bottom of the barrel by the whorl acorn.

With the various spindle components and blanks supported in alignment as shown by Fig. l, the press is operated to bring the plunger adapter socket A loosely into the illustrated embracing relationship to the top end portion 25x of the tip blank and with the inner end of the socket in contact with the flat top end 26y of the blank; and then, by fairly rapid continued uniform rate relative movement of the press ram and platen B, the blanks are forced into final relative position which is essentially that illustrated by Fig. l of the finished composite spindle. It will be apparent that the entire assemblage shown by Fig. 2 might be inverted, although no advantage would be obtained thereby.

The only provision for lubrication found necessary for press fitting, with the spindle parts made in the above described dimensional etc. relationships, are: application to surface portion 56 of the shaft, and to the reduced diameter lower end portion 12 of the barrel blank x, of a suitable lubricant or compound such for example as liquid soap. This can be applied to the shaft 2 and barrel blank 10x (e. g. by dipping) just prior to insertion of those parts into the press.

Referring further to Fig. 2, as the press is closed on the axially assembled blanks insertion of the shank of the tip blank 25x into barrel bore 29 is the first press fitting operation to be performed since the involved diameters are relatively small; the reduced diameter barrel shank 12 then starts to enter the main bore 13 of the whorl acorn 14; then the shaft portions 6 and 5 enter their interfitting bores 8 and 7 (preferably in that order or simultaneously); and finally the joints 30 (tip 25 vs. barrel) and 24 (whorl acorn vs. barrel shoulder 23) are closed tightly, completely around the spindle axis, all in one continuous operation. Since the only possible axial interrelationships between the barrel blank 10x, the whorl blank 15x and the shaft 2 have been established by precision support of the whorl blank and the shaft on and in the platen of the press (dimension Q), axial uniformity of product is insured.

After the smoothly tapered shoulder 38 on the shaft 2 enters its bore 7 in the barrel blank 19x the tubular, reduced diameter, wall of aluminum at the lower end of the barrel blank becomes subjected simultaneously to radially oppositely acting forces which (assuming appropriate selection of alloy and treatment thereof as is well known) effect sufiicient local cold working of the aluminum, further to harden and strengthen it at the critical region, earlier mentioned as being most likely to be subjected to concentrated stress and strain in resisting lateral fiexure of the spindle top portion when the shaft 2 is firmly supported at bearing surface 3.

It will be seen from the above that since all the tightly interfitted parts in the above described construction are basically cylindrical, the parts can be tightly fitted together in any desired precise axial relationship, whereas if interfitted taper surfaces had been used, then it would not only be extremely difiicult to manufacture the involved parts with accurately mating smooth taper surfaces as necessary but there could be only one axial relationship of each pair of taper fitted parts, not a choice of several as in the present subject construction.

While great care is exercised in forming the shaftreceiving and tip-receiving bores 10a and 29 in the opposite ends of the barrel blank in true axial alignment,

and centrally of said blank, it is obvious that absolute concentricity cannot be assured in high quantity production. Accordingly the precision formed shaft 2, the lower portions of which determine the axis of rotation of the spindle in its bolster, are now used, as generally illustrated by Fig. 3, in placing a tool center socket 50 or its operative equivalent in or on the outer end face 26y of the tip blank. Characters 51 and 52 are intended to indicate suitable coaxial supports holding the bolsterbearing-engaging surface 3 and the conically pointed footstep end portion 4 of the shaft 2 in true alignment with center socket forming tool 53. The spindle is afterward mounted in another machine tool, in accordance with accepted practice, using the center socket 50 and the precision formed portions of the exposed end of the shaft 2 (as will be apparent without requiring discussion), to machine the described assembled spindle blank parts as to size and smooth finish. The smooth flush joint at 24 hereof (Fig. 1), at the top of the whorl acorn 14, and the smooth flush joint 30 between the barrel 10 and the bobbin driving tip 25 (Fig. 1), are formed, during the final turning and finishing treatment to remove the excess metal, substantially as described in patent to H. Gleitz et al. 2,582,325, issued January 15, 1952, to the assignee of the present application.

I claim:

1. A composite metal, textile mill spindle blade and whorl unit, comprising a one piece hard steel shaft having a bolster-bearing-engaging circular surface between its ends, a barrel of light weight metal exteriorly formed to support a bobbin and having a bottom axial bore which receives a portion of the shaft lying above its bolster bearing engaging surface, and a substantially rigid steel whorl telescoping the barrel and in interference fitted gripping contact with a lower end portion of the barrel, characterized particularly in that said portion of the shaft has cylindrical regions of relatively different diameters and each of considerable axial extent as compared to the diameters of said shaft portion in interference fitted metal-to-metal mating relationship to the light weight metal of the barrel in said bore, one relatively smaller diameter region being above the upper limit of the whorl and the other relatively larger diameter region being below said upper limit of the whorl and closely adjacent the bolster-bearing-engaging surface of the shaft.

2. The composite spindle construction according to claim 1, wherein the shaft at its lower region of interference fitted contact with the barrel, is of sufiiciently larger diameter than at the upper region so that the two cylindrical portions of the shaft can be force fitted into the barrel, in the absence of temperature difference between the shaft and barrel, and without possibility of the lower bore-defininig cylindrical surface of the barrel being enlarged by passage of the upper cylindrical portion of the shaft therethrough.

3. A composite metal, textile mill spindle blade and whorl unit, comprising a one piece hard steel shaft having a bolster-bearing-engaging circular surface between its ends, a barrel of light weight metal exteriorly formed to support a bobbin and having a bottom axial generally cylindrical bore the defining metal surface of which is in interference fitted metal-to-metal gripping contact with the shaft above its bolster-bearing-engaging surface, and a steel whorl telescoping the barrel and in interference fitted gripping contact with a relatively reduced diameter lower end portion of the barrel, forming a butt joint therewith; characterized particularly in that the shaft has axially spaced apart cylindrical regions in interference fitted relationship to metal defining said bore, between which region, axially of the shaft, the metal of said shaft is in radially spaced relationship to the barrel metal all around the shaft, and the region of such radial spacing extends substantial distances above and below said butt joint.

4. A composite metal, textile spindle blade and whorl unit comprising a central, one-piece, hard steel shaft having a bolster-bearing-engaging surface between its ends, a barrel of light weight metal exteriorly formed to support a bobbin and having a bottom axial bore the defining metal surface of which is in tightly gripping, metal-to-metal contact with the one piece shaft above its bolster bearing engaging surface, and a steel whorl in tightly gripping metal-to-metal contact with the barrel around the lower end portion of the barrel for a considerable distance along it; characterized particularly in that said axial bore of the barrel and the mating portion of the shaft received thereby comprise two axially spaced pairs of mating substantially cylindrical surfaces axially separated by a clearance space all around the shaft and between it and the barrel bore radially opposite a barrel-gripping portion of the whorl, the clearance space being of sufficient radial extent so that the portion of the shaft enclosed by said space can flex without coming into contact with the bore-defining metal of the barrel.

5. As an article of manufacture, a textile mill spindle made entirely of metal and adapted to carry tube type I bobbins, said spindle comprising a central hard steel shaft having a bolster-bearing-engaging surface portion between its ends, an aluminum barrel having an axial bore in its lower end for receiving the upper end portion of the shaft, and a steel whorl having lower and upper flanges and a reduced diameter acorn portion upwardly from the upper flange, which acorn portion and the portion having said upper flange are in tightly embracing force-fitted relation to a reduced diameter generally cylindrical lower end portion of the barrel; characterized particularly in that a cylindrical portion of said upper end portion of the shaft has one tight, interference fitting connection with the bore-defining inner surface of the aluminum barrel in the horizontal plane of said upper flange, and, upwardly beyond the horizontal plane of the top end of the whorl acorn portion, another cylindrical portion of the shaft has a tight, interference fitting connection with the bore-defining inner surface of the aluminum barrel, the portion of the shaft lying axially between the regions of tight contact of the shaft with the barrel metal being out of contact with the barrel metal.

6. The construction according to claim wherein the relationships of interference fitted surfaces of the shaft and barrel are such that the shaft is gripped tighter in the horizontal plane of said upper flange of the whorl than at the upper interfitted surfaces of shaft and barrel above the whorl acorn.

7. A composite, metal, textile mill spindle blade and whorl unit comprising a central steel shaft member adapted to be supported for rotation in a bolster, a light weight metal barrel member permanently telescoping an upper end portion of the shaft member in interference fitted relation thereto, said barrel member being adapted to support a bobbin, and a steel whorl member for driving the unit, which whorl member surrounds and is in permanent telescoping interference fitted relationship to a lower end portion of the barrel member in regions radially aligned with said interference fitted upper end portion of the shaft member in the barrel member; characterized particularly in that cylindrical mutually mating surface portions of two of said members are axially spaced apart by means providing continuous clearance between the two members all around the inner member of sufiicieht axial extent to permit substantial 10 flexure of the inner member and suflicient radial extent to prevent frictional contact between the two members in event such fiexure occurs.

8. The construction according to claim 7, further characterized in that the two mating surface portions of said two members are of different diameters, and the means providing said clearance is a cylindrical counterbore in the outer of said two members.

9. A composite metal, textile mill spindle blade and whorl unit, comprising a one piece hard steel shaft having a bolster-bearing-engaging circular surface between its ends, a barrel of light weight metal exteriorly formed to support a bobbin and having a bottom axial bore the defining metal surface of which is in interference fitted metal-to-metal gripping contact with the shaft above its bolster-bearing-engaging surface, and a steel whorl telescoping a lower end portion of the barrel and in interference fitted gripping contact therewith; characterized particularly in that the shaft has axially spaced apart regions in interference fitted relationship to metal defining said bore, between which regions axially of the shaft, the metal of said shaft is in radially spaced relationship to the barrel metal all around the shaft, and the region of such radial spacing extends substantial distances above and below the plane of the upper end of the whorl.

10. As an article of manufacture, a composite metal spindle for textile mills, said spindle comprising a onepiece hard steel shaft having a bolster-bearing-engaging circular surface between its ends, a bobbin-supporting barrel of light weight relatively soft metal having an axial bore in its lower end portion telescoping the upper end portion of the shaft above its bolster-bearing-engaging surface, and a steel whorl surrounding and tightly embracing a lower end portion of the barrel radially opposite the telescoped portion of the shaft, characterized particularly in that the axial bore of the barrel, as formed prior to assembly with the shaft, has a lower cylindrical counterbore portion and an upper reduced diameter cylindrical portion, and the telescoped portion of the shaft has correspondingly located relatively different diameter cylindrical portions the larger of which is close to said bolster-bearing-engaging circular surface portion of the shaft, said cylindrical portions of the shaft being appropriately larger than respective relatively different diameter portions of said bore for tight press fitting engagement therewith at uniform temperatures of the mutually telescoping portions of the barrel and shaft, whereby the barrel and shaft can be assembled by press fitting at such uniform temperature without possibility of the upper cylindrical portion of the shaft impairing the tight fitting of the shaft and barrel close to said bolsterbearing-engaging portion of the shaft during such assembly operation.

References Cited in the file of this patent UNITED STATES PATENTS 244,548 Chapman July 19, 1881 245,487 Hall Aug. 9, 1881 2,170,727 Mitchell Aug. 22, 1939 2,417,485 Gleitz Mar. 18, 1947 2,485,959 Davies Oct. 25, 1949 2,536,618 Wood Jan. 2, 1951 2,555,652 Mandouchitch June 5, 1951 

